The present invention relates to pipe joints.
Pipe joints are already known which comprise a pair of tubular joint members of stainless steel each having an abutting end face, an annular gasket of stainless steel interposed between the abutting end faces of the respective joint members, and a nut joining the joint members together and formed in its side wall with an inspection window at a position corresponding to the abutting end faces of the joint members, the inspection window extending through the nut side wall radially thereof.
The problem which is likely to be experienced with pipe joints of the type described is that the worker forgets to install the gasket, permitting a fluid to leak from the joint as incorporated in piping, so that it is practice to check the joint for the presence of the gasket through the inspection window before the nut is tightened up.
The conventional pipe joint has the problem that since the joint members and the gasket are made of stainless steel, it is difficult to discern whether or not the gasket is provided between the abutting end faces of the two joint members and to recognize the presence of the gasket. Besides stainless steel, aluminum, nickel, titanium and the like metals are used for making the joint members and gasket, whereas the same problem is also encountered with these metals because they are all similarly silver white.